security forces in pakistan's largest city, karachi, have been authorized to shoot on sight anyone they believe is involved in violence. at least 65 people have been killed in gratia since tuesday. the current unrest is blamed on armed gangs. many shops and foreign offices were closed. here is this report. >> armed troops to stand on guard on the streets of pakistan's business and commercial capital. three days of violence have been the worst karachi has seen this year. target killings and drive-by shootings are widely blamed on armed gangs linked to rival political parties. >> killing and violence has increased so much. no one is safe anymore. >> this is the heart of karachi's main shopping thi district. as you can see, today they are deserted. most people did not go to work or open businesses because they are afraid of more violence. >> many of those who were shot dead were ordinary people going about their daily lives. some were killed just for their ethnicity. the most powerful political party here, mqm, represents the curfew speaking majority. -- erdu speaking majority. last week,